Two-way fiber optic communications links are often implemented using separate fibers for the transmitted and received data signals. Using separate fibers may result in reduced noise and crosstalk in comparison with using a single fiber for handling both signals.
Typically, a conventional duplex connector consisting of two independent connectors joined by a plastic housing is used for making optical connections in such two-fiber systems. Each of the connectors comprising the conventional duplex connector is coupled to one of the optical fibers. Each of such fibers is separately cabled, and the two optical fibers are usually connected to separate transmitter and detector devices.
Each of the connectors forming the duplex connector includes a cylindrical ferrule, typically ceramic, which receives the optical fiber in a single hole running along the axis of symmetry of the ferrule, i.e., the center of the ferrule. Locating the hole through the center of the ferrule aids in fabricating the ferrule with the sub-micron tolerances required for single mode fiber alignment.
It would be preferable to hold two fibers in a single ferrule. Such a ferrule would facilitate using a single connector, rather than two joined connectors, for duplex fiber handling. Since the cost of the conventional duplex connector described above is about equal to that of two separate simplex connectors, using a single connector for this service would provide a significant cost savings. The manufacturing techniques used for forming conventional single-fiber ferrules, i.e., forming a single hole at the center of the ferrule, cannot be used, however, for forming two holes positioned with the accuracy required for single-mode fiber alignment.
Thus, a ferrule suitable for receiving two optical fibers, methods for its manufacture, and photonics connectors and packages incorporating such a ferrule would be desirable.